In the UK, when you apply to work with vulnerable people, particularly children you have to get confirmation from the police that you don't have a history of crime involving children before you can start work. You apply to the CRB, (criminal record board) and after what seems like an eternity, you get a piece of paper back confirming whether or not you have a criminal record.

In fact, my question referred to a piece of paper issued by a school (elementary) to indicate that a student has had good behavior during the school year (sort of a recommendation letter). Criminal record check and Police Statement sound more serious. I guess they would be equivalent to our Carta de No Antecedentes Penales.

Letter of Good Conduct sounds fine to me, but any further feedback is welcomed.